Valve grinding device for engines



Nov. 26, 1940.

A. G. F. WALLGREN VALVE GRINDING DEVICE FOR ENGINES Filed Aug. 15, 1939 Patented Nov. 26, 1940 UNITED STATES VALVE GRINDING DEVICE FOR ENGINES August Gunnar Ferdinand Wallgren, Eskilstuna,

Sweden, assignor to Aktiebolaget Bolinder- Munktell, Eskilstuna, Sweden, a corporatio of Sweden Application August 15, 1939, Serial No. 290,160 In Sweden August 16, 1938 10 Claims. (Oi. l23-198) The present invention relates to valved engines and has particular reference to internal combustion engines of the kind having one or more valves for controlling the flow of cylinder gases such, for example, as inlet valves for the admission of air or combustion gas to the cylinder or exhaust valves for discharging combustion gas therefrom.

In engines of this character, the valves usually require periodic attention owing to the development of gas leakage past the valves because of wear, corrosion, pitting, etc. of the valve surfaces. Ordinarily, the valves are reconditioned by grinding Operations performed on the engine at its place of installation, and the present invention has for a. principal object the provision of novel valve grinding means which in addition to its function as a valve grinding device, also has the further function of constituting a portion of 2L) the engine structure which is essential to the operation of the engine.

A further object is the provision of a valve grinding member which is provided with special grinding surfaces and which may be employed to grind both the valve seat surfaces and the seating surfaces of the valve member.

By the provision of valve grinding means of the above character which also constitutes a part of the engine structure essential to engine operation, the valve grinding member is necessarily always available for valve grinding purposes and inability to perform valve grinding operations at any time owing to the lack of a suitable valve grinding tool is accordingly eliminated. This is particularly advantageous in the case of engines having special forms of valves for which standard valve grinding apparatus, which is usually readily available, cannot be employed.

'By way of example to illustrate the principles of the invention,'the invention is hereinafter described in connection with a two stroke cycle internal combustion engine operating with crank case compression for scavenging, and the valve grinding member is in this instance made a part 5 of the engine essential to its operation by being employed as a closure member for sealing an opening in the engine crank case which must be closed in order that the crank case compression essential to the operation of the engine can 60 be effected. It. will be understood, however, that in so far as the broader aspects of the invention are concerned, the valve grinding member may be incorporated in diiferent ways in diilerent types of engines so as to perform a function ll essential to the operation of the engine.

For a better understanding of the nature of the invention, its objects and the advantages to be derived from its use, reference may best be had to the ensuing portion of this specification in which a form of apparatus suitable for carry- 5 ing the invention into eflect is described, reference being had to the accompanying drawing forming a part hereof in which:

Fig. l is a transverse sectional viewof a two stroke cycle crank case compression engine of 10 the scavenging type to which the invention is applied;

Fig. 2 is a fragmentary section on enlarged scale showing the valve structure of the engine shown in Fig. 1; and 15 Fig. 3 is a fragmentary section on still larger scale showing a valve grinding member applied in accordance with the invention.

Referring now more particularly to Fig. 1 of the drawing, the engine illustrated is of the two 20 stroke cycle crank case compression type in which scavenging and combustion air is delivered to the engine cylinder from the crank case through piston controlled ports in which the cylinder is scavenged through a mechanically actuated ex- 25 haust valve located in the cylinder head. In the drawing, l0 represents the engine cylinder and I2 the crank case. The cylinder is provided with a piston I4 connected by means of the rod IE to the crankshaft IS in the usual manner. Air is so drawn into the engine crank case through the inlet 20 controlled by the check valve 22 and during the downward or working stroke of the piston is compressed in the crank case for delivery to the engine cylinder throughthe piston 35 controlled transfer passage 24 communicating with the lower portion of the cylinder and adapted to have its outlet and uncovered by the piston as the latter approaches the end of its working stroke. For the discharge of gases from the 40 engine cylinder, the cylinder head 26 is provided with an exhaust valve indicated generally at 28, this valve being mechanically actuated by any conventional form of valve actuating mechanism (not shown) so as to open and close at the proper time in the cycle of operation of the engine cylinder.

In the embodiment illustrated, the valve is of the annular type having a valve head 28a provided with flat circular inner and outer valve faces 28!) and 280, respectively, which engage the respective valve seats 30 and 32 formed on the inner face of the cylinder head. The valve head is further provided with a circular projection or flange 28d projecting into the annular gas pasu sage 88 communicating with the valve opening between the seats 38 and 32. The flange 28d serves to stiffen the valvehead and prevent the latter from warping under the influence of the high temperature conditions obtaining and is actuated through the medium of a plurality of valve stems 286 (preferably three in number) which extend through the valve head structure in suitable guides for operative contact with the valve actuating mechanism. The valve per se and its specific method of mounting form no part of the present invention, and constitute the claimed subject matter of my copending application Serial No. 290,159, filed August 15, 1939.

'In accordance with the invention, a valve grinding member is provided which in the present instance is indicated generally by reference numeral, 38. As shown more clearly in Fig. 3, this member comprises concentric inner and outer circular wall portions 38 and 48 respectively connected to a bottom portion 42. At one end the circular wall portions 88 and 48 are provided with end surfaces 84 and 48, respectively, formed of any suitable valve grinding material which may be secured to the body of the grinding member by any suitable means, and which may advantageously be in the form of an adherent coating of abrasive. At the opposite ends of the cylindrical wall surfaces, valve seat grinding surfaces 48 and 58 are provided, which surfaces may, like the surfaces 44 and 46, be composed of special valve grinding material suitably secured to the valve grinding member. A circular projection 52 is advantageously provided between the valve seat grinding surfaces 48 and 58 and for the type of valve described, the walls 38 and 48- are also advantageously provided with the confronting guide surfaces 54 and 56, respectively.

In its function as a valve grinding device, the operation of member 36 willbemoreor less obvious from the drawing, wherein in Fig. 3 the valve 28 is shown in broken lines in position relative to the valve grinding member for the valve by relative rotation of the valve with respect to the grinding member, the projections and 58 serving during this operation to properly center the valve with respect to the grinding member.

It will also be evident that with the valve re= moved from the cylinder head, the valve grinding member 38 may be applied to the inner face of the head with the grinding surfaces 48 and 58 in contact with the surfaces 38 and 82, the pro- Jectlon 52 on the valve grinding member extending into the valve opening and operating as'a guide to properly center the parts during the grinding operation when the grinding member is rotated with respect to the head.

V It will be evident that if it is to be insured that a proper valve grinding operation may be carried out at the place of installation of the engine, the valve grinding member must always be available and in order to insure this, the valve grinding member is utilized in the present instance as a closure member for the crank case structure, which is essential to the operation of the engine. In the arrangement shown, the crank case structure i2 is provided with a lid member I8 having an opening 58 which is closed by the aid of the valve grinding memben' Lid member 18 is detachably secured to the crank case by screws 12. In the embodiment shown the opening 58 is closed by clamping the base portion of the member 35 over the opening by means of a clamping plate 88 and stud 62 passing through the clamping plate and the opening and screwed into a suitable threaded opening 64 in the base portion 42 of the valve grinding member.

With the valve grinding member in its position as a closure member for the crank case, as indicated in Figs. 1 and 3, it will be evident that the engine may operatein accordance with its proper cycle of operation and it will be equally evident that in the absence of the valve grinding mem-f ber in its proper position, operation of the engine will not be possible owing to the impossibility of effecting compression within the crank case. Cnsequent1y,.with the valve member constituting an element essential to the proper operation of the engine. it will'always be necessary to replace this member on the engine after the completion of any valve grinding operation before the engine can again be started and since the continued performance of the valve grinding member in its proper position is essential to the continued operation of the engine, this member will necessarily always be available whenever the next succeeding valve grinding operation must be performed.

In the preferred form the wall 14 forming the opening 58 has a conical surface 16 coacting with a sealing surface 18 of the grinding member 36 of corresponding shape. The outer end of the wall 14 is recessed as at 88. The opening 58 can consequently not be closed by a plane plate.

Obviously the principles of the invention may be carried out in different specific ways which will suggest themselves to those skilled in the art and the invention is accordingly to be understood as not limited to the example herein given by way of illustration but as embracing all apparatus falling within the scope of the appended I claims.

What is claimed is: l

1. A valve grinding device for engines comprising a member having grinding surfaces and adapted to be employed as a part of the engine structure essential to the operation of the engine.

2. A valve grinding device for engines comprising a member having grinding surfaces for grinding both the ,valve seats and the valve faces of the engine valves and adaptedtobe employed as a part of the engine structure essential to the operation of the engine.

3. The. combination, with a valved internal combustion engine of a member detachably secured to the engine and required to be in its attached position in order for the engine to be operated, said member having grinding surfaces thereon for grinding the engine valves when the member is detached from the engine.

4. The combination, with a valved internal combustion engine of the crank case compression type, of a member detachably secured to the engine and required to be in its attached position in order for compression to be effected in the crank case, said member having grinding surfaces for grinding the engine valves when themember is detached from the engine.

5. The combination, with a valved internal combustion engine of the crank case compression type and having a crank case opening therein of a member having a portion adapted to engage the crank case to effect closure of said opening and portions providing grinding surfaces for grinding'the engine valves, and means for securin; the member to the crank case in detachably engaging relation.

6. The combination, with an internal combustion engine having an annular valve opening and a valve for closing said opening, oi a valve grinding member having annular grinding surfaces shaped to grind the valve seats and valve faces and having a portion required to be in engagement with a, portion of the engine structure to permit the engine to be operated, and means for detachably securing the last mentioned portion in operative engagement with the engine.

7. A valve grinding device for an engine having an annular valve opening and cooperating annular valve, comprising a unitary member having spaced annular grinding surfaces and means for guiding said surfaces rotationally with respect to the surfaces to be ground thereby.

8. A valve grinding device for an annular engine valve having spaced annular faces comprising a unitary member having spaced walls providing spaced annular grinding surfaces for grinding spaces, and guide surfaces on the confronting faces of said walla adapted to be engaged by the valve head to guide the valve peripherally with respect to grinding member during the grinding operation.

9. A valve grinding device for an engine having an annular valve opening bounded by spaced annular valve seats comprising a unitary valve member having spaced annular grinding surfaces adapted to engage said seats and means projecting axially from between the grinding surfaces and adapted to engage the walls of the valve opening to guide the grinding member peripherally with respect to the valve seats during the grinding operation.

10. A valve grinding device comprising a unitary member having grinding surfaces at its opposite ends for grinding a valve face and a valve seat respectively, and means providing guide surfaces adapted to be engaged by'a valve member and the wall of a valve port opening, respectively, for grinding said member peripherally with respect to the surface being ground.

AUGUST GUNNAR FERDINAND WALLGREN. 

